1. Field of the Invention
The present invention is generally directed to broadband communication systems. In particular, the present invention relates to broadband communication systems that comply with the Data Over Cable Service Interface Specification (DOCSIS), including but not limited to DOCSIS-compliant cable modem communication systems.
2. Background
Conventional cable modem systems utilize DOCSIS-compliant equipment and protocols to carry out the transfer of data packets between multiple cable modems at the customer premises and a cable modem termination system (CMTS) at the cable headend. The term DOCSIS (Data Over Cable System Interface Specification) generally refers to a group of specifications published by CableLabs that define industry standards for cable headend and cable modem equipment. In part, DOCSIS sets forth requirements and objectives for various aspects of cable modem systems including operations support systems, management, data interfaces, as well as network layer, data link layer, and physical layer transport for data over cable systems, The most current version of the DOCSIS specification is DOCSIS 2.0.
It has been observed, however, that the use of proprietary features or protocols that are not provided for, or permitted by, the DOCSIS specification may be advantageous within a DOCSIS-compliant cable modem system. For example, the modification of certain DOCSIS-defined physical (PHY) layer or Media Access Control (MAC) layer parameters and/or the use of different PHY or MAC technologies than those supported by DOCSIS may provide a variety of benefits. Such benefits can range from providing better system throughput, reducing latency, reducing the cost of the cable modem and/or the CMTS, providing a system with better signal integrity, providing improved utilization of the spectrum, reducing the area of either the cable modem or the CMTS, or providing better noise immunity.
Heretofore, such use of proprietary features that extend beyond DOCSIS has been avoided. This is due, in part, to the fact that the DOCSIS specification does not provide a mechanism for implementing proprietary features. Moreover, because conventional CMTS and cable modem equipment have been designed in accordance with the DOCSIS specification, the implementation of proprietary features has been avoided to ensure interoperability between cable modem system components.
Accordingly, what is desired is a system, method and computer program product that enables the use of proprietary features that are not provided for, or permitted by, the DOCSIS specification within a DOCSIS-compliant broadband communication system, such as a DOCSIS-compliant cable modem system. For example, the desired system, method and computer program product should support the modification of DOCSIS-defined physical (PHY) layer or Media Access Control (MAC) layer parameters and/or the use of different PHY or MAC technologies than those supported by DOCSIS. However, the desired system, method and computer program product should also be interoperable with DOCSIS in the sense that system components that support the proprietary features can exist on the same network with standard DOCSIS-compliant components that do not. Furthermore, the desired system and method should be implemented in a manner that requires minimal modification to the design of existing system components, such as the design of existing cable modem and CMTS equipment.
The features and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawings in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.